1. Field of the Invention
The invention relates to a ski or a snowboard in the form of a board-type gliding device and a method of producing a corresponding ski or snowboard.
2. Prior Art
Patent specification EP 1 297 869 A1 discloses a gliding snowboard, in particular a ski, and a prising mechanism for its gliding board body. The width of the gliding board body can be varied across at least a partial length by means of this prising mechanism. The prising mechanism thus causes the gliding board body to prise open depending on the load or flexing of the gliding board body. This prising mechanism comprises a plurality of prising levers disposed in pairs, which cause the gliding board body to be prised apart in the region of a slot at the rear end of the ski. The slot, which becomes wider and narrower as a function of load, is therefore disposed at a rearward end of the gliding board body. When the prising mechanism is operated with a view to reducing or increasing the angle subtended by the two prising levers, the rear end of the gliding board body is prised open. In the case of another embodiment, an adjusting element may be provided, by means of which the prising element of the prising mechanism can be pre-set. With the proposed designs, the rear end of the gliding board body is slotted and the prising mechanism is integrated inside the slot or the resultant recess, which occupies approximately one third of the ski width. The described prising mechanism is of a relatively complex construction and the change which can be achieved in terms of the travel or turning behavior of the gliding board body with the previously known design can be made to a significant degree only if the rear end of the gliding board body is subjected to a relatively strong, elastic prising action. In order to obtain pronounced changes in the geometry or travel behavior of the gliding board body, therefore, it is necessary to produce strong deformations or elastic prising forces at the rear end, as a result of which the loads acting on the gliding board body can rapidly reach a problematically high degree or the desired extent of variations in the travel behavior can be achieved, but only with great difficulty due to the fact that the adjusting forces are not strong enough for the prising mechanism.
Patent specification DE 43 24 871 A1 describes a gliding board body, which may be made up of three structurally separate board-type elements. In particular, a gliding board, especially a snowboard, is made up of a total of two skis and a middle part disposed in between, additionally using plates. Disposed in the middle portion of the gliding board is a clamping means, by means of which the skis disposed to the side of the middle part can be clamped with respect to one another causing an elastic deformation in its transverse direction, thereby enabling the gliding board to be adjusted to the desired contour radius. When the two outer skis are clamped to one another by the clamping means, the gap becomes smaller and smaller as the ski becomes more deformed in the transverse direction until it disappears altogether when the two skis lie in full abutment with the middle part. As a result of this clamping action and deformation of the skis, the contour radii which are ultimately in imparted to the fully assembled gliding board or snowboard are significantly smaller than those of the skis. The disadvantage of this is that this gliding board is awkward to handle and the requisite components, in particular the plate parts, are mechanically complex and significantly increase the overall weight of the gliding board body.
Patent specification DE 34 44 345 A1 describes a so-called double-runner ski, whereby two runners of a ski extend parallel with one another and curve upwards at the two mutually joined ends. However, it is also possible to provide several, in particular three or four, runners per ski extending parallel with one another, in which case they are joined at their oppositely lying ends to form a unit. The slot between the double runners extending longitudinally down the centre is intended to permit snow which has built up in front of the tip of a ski to flow away more efficiently. Rounded inner edges of the two runners are intended to make the ski easier to rotate or turn. However, the proposed designs have only a limited use in practical applications.
Document DE 85 12 315 U1 describes a ski, the rear portion of which is split by means of a slot. The width of the slot can be made smaller and bigger by means of an adjusting element so that the rear portion of the ski can be varied in terms of the contour of its side edges. Although the slot in the rear end of the ski body enables changes to be made to the ski geometry, the extent of the changes is only satisfactory under certain conditions, given that the capacity of the rear ski end to prise open is limited by structural and design constraints.
Document DE 84 22 316 U1 describes a ski, the front and rear portion of which have longitudinally disposed slots extending from the binding mounting portion towards the front and towards the rear and terminating just short of the respective end of the ski, thereby resulting in integral, transversely stable ski ends. By means of respective co-operating adjusting elements, the width of the slots can be varied, thereby enabling the contours of the side edges to be varied independently of one another in the front and rear portion of the ski. The disadvantage of this approach is that the geometry which can be set using this construction causes the contours of the side edges to become non-homogeneous or non-uniform relatively quickly which is detrimental to the control behavior of the ski. In particular, it becomes more difficult to “ride on the edge”, which is in important to the dynamics or acceleration of the ski when starting to turn, which can cause problematic skidding phases during turning.
Patent specification DE 24 17 156 A1 describes a ski comprising at least two gliding strips disposed adjacent to one another. These gliding strips are joined to one another by fixing means to permit a relative movement of the two gliding strips in the vertical direction with respect to their gliding surface, at least in their middle portion. This results in a multiple, in particular twofold, edge support, which is intended to produce a better grip to prevent lateral skidding. The mechanical coupling between the two gliding strips requires complex mechanisms, which means that a design of this type is of only limited practical value.
Patent specification FR 2 794 374 A1 discloses various designs for changing geometry, in particular of the side edge contour of a ski. In one of the proposed embodiments, both ends of the ski may be provided with slots, which extend beyond the end of the ski, resulting in longitudinally extending cuts in the oppositely lying ends of the ski. Close to the front and rear end of the ski, adjusting means are provided, which are mechanically coupled or act independently of one another and enable the respective ends of the ski to be made narrower or prised open. Although these features enable the travel properties of the ski to be influenced to a significantly higher degree, the performance which can be achieved with such a gliding device is still not particularly satisfactory.
Patent specification EP 1 516 652 A1 describes a snow gliding board, in particular a snowboard, which has a recess in at least one of its ends, in which an insert is fitted. This insert is designed so that it has at least one mound or recess on its bottom face, which is open towards the bottom face of the gliding board body. The insert is made from a permanently deformable material, in particular a thermoplastic polymer or plastic, which is permanently deformed to a cambered shape standing proud of the top face of the gliding board body during the process of manufacturing the snowboard. These recesses or cut-outs in the running surface of the snowboard are intended as a means of positively influencing the flow of snow and aiding gliding in the snow. Especially in the case of powdery snow, the intention is to produce a better guiding action for the snowboard and a reduced resistance in the rearward shovel region. In particular, the intention is to improve deep snow properties for a snowboard. An individual change in the guide properties, in particular the turning behavior, of the snowboard is not possible, however, due to the fact that the insert piece fitted in the recess is made from a permanently deformed, thermoplastic plastic material.
Document DE 201 13 739 U1 describes a snowboard, which has a slot essentially along its mid-axis, extending from the rear end of the gliding board body at least as far as its middle portion, thereby forming two rear arms separated from one another, which are joined to one another by the integral front portion. This slot extends from the rear to the front in a wedge shape tapering to a point, and the slot in the rear portion of the snowboard is wider than in the middle portion of the snowboard. In addition, this slot may merge into a recess which extends in the direction towards the front portion of the snowboard, gradually disappearing. An adjusting mechanism is also provided, which acts on the two legs of the snowboard and is provided in the form of a threaded spindle arrangement. This enables the distance between the two legs to be adjusted and to be so in the pulling direction, i.e. so that the slot becomes narrower, as well as in the pushing direction, i.e. so that the slot becomes wider. Consequently, the contour and hence the travel behavior of the snowboard can be individually varied to a certain extent. The disadvantage of this approach is that the slot in the gliding board body, which extends from the rear end across more than half of the total length of the gliding board, is made up of two legs which run away from one another independently across extensive portions and are therefore subjected to high loads. In particular, the gripping ability of the edges or tracking of such a design are only satisfactory under certain conditions because high torsional loads act on the relatively narrow legs of the snowboard during turning, which can cause relatively pronounced twisting of the legs about their longitudinal axis. Especially if edge loads occur, as is often the case with cut swinging actions in particular, the tracking and stability desired by the user are difficult to obtain.